1. Technical Field
This application is an extension of application Ser. No. 25,066 filed Mar. 12, 1987, U.S. Pat. No. 4,758,349. To be more specific, this invention is broadly related to an apparatus and methods to isolate a desired component or multiple components simultaneously, from a solution containing a plurality of mixture components. The apparatus is advanced by its unique construction to convey the novel separation method to leave the native engineering drawbacks of current chromatographic process become irrelevant, such as back mixing and diffusion, axial dispersion, and column end effects. By applying the differential set-up between solid and liquid phase, new mass transfer contacting method, and operation protocols, this apparatus dramatically increases mass transfer efficiency and effectively utilizes packing materials in comparison with chromatographic process under same feeding capacity requirement. The process further controls the system separation parameters to avoid deterioration of separation efficiency due native engineering drawbacks of chromatographic process.
2. Description of Prior Art
The review of prior literature and current survey of commercial chromatography involves with chemically adsorption and de-adsorption interaction of so called mass transfer phenomena between the solid and component mixtures in liquid phase. It indicates the packed or fixed bed batch type columns are the dominant device being widely used for separation. Ever since 1967, the liquid chromatography was first emerged by Huber and Hulsman for faster and easier analytical speed over gas chromatography. Until nowadays that simulated moving bed process employing the embodiments as described in U.S. Pat. Nos. 3,761,533 and 3,201,491 become well known and adopted for such purposes. In those known processes, a chromatographic column is divided into several sections by distributors that allow fluid to flow into or out of each section. Those sections are interconnected in order and continuously circulating fluid stream flowing through all sections by circulating the effluent fluid from an outlet of the last section to an inlet of the first section. At a setting time intervals, all the points of introducing and withdrawing the inlet and outlet streams are shifted simultaneously as same direction of fluid flow; this gives the packing materials a simulated flow in opposite direction of fluid flow. Alternatively, the multiple columns continuous solids and liquids contacting device, as taught by the U.S. Pat. No. 4,522,726 and continuation-in-part of 4,522,726 which is U.S. Pat. No. 4,808,317. This device is described by its structure to provide fixed inlet and outlet nipples for introducing and removing fluid streams. The inlet and outlet nipples are interconnected by a rotating columns which are divided into three or four sections, similar to above mentioned simulated moving bed process. By the nature of ratable construction of its member and plural sections, a discrete fluid streams may simultaneously be treated.
All of above mentioned processes comprise certain differences. However, they are all fallen into same categories that apply a stationary packing material within the circular column with an attempt somewhat in manipulating the column configurations and optimization in fluid distribution. The separation is achieved through sequential stages as feed adsorption, selectively desorption to elute impurities and product via specific elution streams, adsorbent regeneration and washing. As thumb of chromatographic operation, the liquid stream is being pushed from one end of column and the existing fluid to emerge from the other end of column. When the fresh feed is delivered, the adsorption of solute components onto the adsorbent occurs. The adsorbent is being consumed and saturated with solutes slowly from one end of the column as feed stream flow direction. At any given instance, the mass transfer is proceeded in a very small trace of adsorbent wherein the mixed zone of two consecutive liquids travels through the bed. The rest of the packing materials are idle for either as saturated adsorbent or waiting to be saturated. The adsorbent is inefficiently being consumed mainly because the idle of most part of packing materials. The same situation is repeated for elution and regeneration stage. In view of unemployed packing materials, the required amount of mobile phase is proportional increased with processing time in which the cycle time engaged for each consecutive stage are accumulated for stages of feeding, multiple impurity stripping and regeneration. For instance of eluting a particular solute component, the specific fresh eluent is required to push from one end of the column and travel through the entire bed to emerge from the other end of column. This shall be compelled to create dilution of separated fractions due engineering drawbacks, of which often involves with the combined effects of axial dispersion, back mixing, and end effects for fluid in and out of column. Those combined fluid dynamic phenomena have great impacts on product purity and process efficiency such that the feed loading limit is crucial and the separated peaks may often mixed up again with the neighboring peaks. The production rate has to be compromised with purity. Thus, the separation efficiency is low. The mass transfer mechanism justifies the chromatography has natural deficiencies on loading limitation and deteriorating separation, particularly in large industrial separation process. The typical batch chromatographic operation is a tedious process resulting in considerable downtime and often requiring complicated protocols and expensive support systems. The scale up of a typical column process for large-scale purification usually battles with not only the loading limitation for acceptable quality but also requires high-pressure operation and high-energy consumption. Furthermore, the scale up usually is linear procedures from pilot scale through which involves all concerns of not only cost of construction but higher probability of failure.
It is readily understood that the breakthrough of efficient consumption of packing materials not only shall provide a gifted separation process to triumph the native engineering deficiencies of traditional chromatography. It also markedly improves the efficiency of existing separation processes in aspects for low operation cost, low equipment investment, and flexible separation protocols.